Jobs said that people wanted a MacBook with a metal enclosure, faster graphics, and LED backlit displays, and Apple delivered on all of those counts: like the MacBook Pro, the MacBook features a unibody aluminum case carved from a single piece of aluminum, an LED-backlit display, and the new GeForce 9400M graphics processor, which sports 256MB of DDR3 shared with the main system memory.

In addition to increased performance and power efficiency, the Nvidia chipset also allows the MacBooks to drive an external display at 2560 by 1600 pixels at millions of colors, a step up from the 1920 by 1200 resolution supported by the previous generation’s Intel GMA X3100 graphics processor.

Physically, the new MacBooks are similar in shape to their predecessors, with the same 13.3” screen running at 1280 by 800 pixels with support for millions of colors. In size it has the same 12.78 inch width as before and a marginally larger depth of 8.94 inches compared to the old model’s 8.92 inches. The new MacBooks are thinner, though, at just 0.95 inches compared to the white and black models’ 1.08 inches, and they shave half a pound off their predecessor’s weight, coming in at 4.5 pounds.

The new MacBooks look almost identical to their MacBook Pro siblings, with the same black bezel around the screen and the same keyboard style that debuted on the original MacBook in 2006. However, only the higher-end 2.4GHz model features the illuminated keyboard also found on the MacBook Pro and MacBook Air.

One of the most touted new features of the updated MacBook line is the glass multi-touch trackpad, which supports gestures of anywhere between one and four fingers. During the product unveiling today, Jobs demonstrated a new four-finger swipe gesture that could activate the Expose feature of OS X, and another that would summon the OS’s application switcher. The trackpad also eschews a separate trackpad button: instead, the whole trackpad acts as a physical button that you can click.

The MacBook’s assortment of ports has also undergone some changes in this incarnation. Apple has replaced the mini-DVI port featured on earlier models with a mini DisplayPort connector, a new standard connector for computers and monitors created by the Video Electronics Standards Association (VESA). Also gone is the MacBook’s FireWire port. The MagSafe, Gigabit Ethernet, two USB 2.0, and audio in and out ports all remain the same.

Also the same as the prior models is support for 802.11a/b/g and draft N wireless networking, Bluetooth 2.1 + EDR, the iSight camera, built-in omnidirectional microphone, Kensington lock slot, and built-in stereo speakers.

Battery life also gets a small boost in the new model, with Apple promising 5 hours of wireless productivity for the new models, an improvement over the 4.5 hours claimed for the previous incarnations. Apple has also moved the battery meter from the bottom of the MacBook to the left hand side. Like the Pro, the new MacBook features a removable door on the underside that allows the user to remove and replace the MacBook's drive and battery; the MacBook's memory can be upgraded through the same access point, though it requires the removal of an additional 8 screws.

Power’s not the only place that Apple has made environmental improvements. The new MacBooks are specifically designed to be greener, with a highly recyclable aluminum and glass enclosure. Apple’s also removed a number of potentially harmful materials from the laptops, including mercury, arsenic, brominated flame retardants (BFR), and polyvinyl chloride. Jobs also pointed out that the packaging was 42 percent smaller than before, and that, like the MacBook Pro, the MacBook had garnered an EPEAT Gold certification for its environmental friendliness.

The MacBook comes in two flavors. For $1,299 you get a 13.3-inch display, 2GHz Core 2 Duo with 3MB L2 cache, 2GB 1066MHz DDR 3 memory, GeForce 9400M, a 160GB hard drive, and a slot-loading SuperDrive; build-to-order options include a 250GB hard drive for $100, a 320GB hard drive for $200, or a 128GB solid state drive for $700.

The higher-end model costs $1,599 and comes with a 2.4GHz processor, 250GB hard drive, and a backlit keyboard in addition to the features listed above. A 320GB hard drive is available as a build-to-order option for $100, and a 128GB solid state drive costs $600.

Apple will also continue to make the white plastic MacBook with a 2.1 GHz Intel Core 2 Duo processors, 1GB of RAM, a 120GB 5400 rpm hard drive, and a slot-loading 8X SuperDrive and sell it for $999.

Updated at 1:34 p.m. PT with more information on the new MacBooks.

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